Full Text:
The social amoeba Dictyostelium discoideum, or Dicty for short, is a powerful social study system because of the hard work of generations of cell and molecular biologists who have figured out many of the mechanisms of its social process. But it takes studies in nature to understand whether Dicty's cooperative behavior benefits relatives, and even whether its social activities occur frequently in nature.
Triggered by starvation, tens of thousands of formerly independent Dicty amoebae aggregate into a motile slug that ultimately differentiates into a fruiting body with living spores aloft a stalk made of sterile stalk cells. About 20 percent of the cells sacrifice themselves to form the stalk that lifts living spores aloft and helps them disperse. This clear separation into altruists (dead stalk cells) and beneficiaries (living spore cells) is reminiscent of an ant colony, where the sterile workers assist their queen in reproducing. Shown here: Dictyostelium discoideum fruiting bodies showing the stalk made up of cells that died to lift the spores to facilitate their transport by insects.Image credit: Tyler Larsen/Washington University
